All-electric mobile power unit with variable outputs

ABSTRACT

An all-electric, battery powered industrial or commercial mobile power unit is provided that can include a number of features. The mobile power unit can include a DC electrical energy source configured to produce a voltage of approximately 300-450 VDC. The mobile power unit can be configured so as to produce a user programmable voltage output and/or a user selected voltage output of either 480 VAC 3-phase, 208 VAC 3-phase, or 240 VAC single-phase. The various output configurations are controlled by software with a system controller of the mobile power unit. Methods of use are also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 17/336,142 titled “ALL-ELECTRIC MOBILE POWER UNIT WITH VARIABLEOUTPUTS,” filed on Jun. 1, 2021, now U.S. Pat. No. 11,283,273, whichclaims the benefit of priority of U.S. Provisional Application No.63/033,120, filed Jun. 1, 2020, which is herein incorporated byreference in its entirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

FIELD

The present application relates generally to industrial power generatorswhich provide temporary power to industries such as construction, film,entertainment, power and utility, electric vehicles, and telecom. Morespecifically, this disclosure provides a novel all-electric industrialmobile power unit with a variety of features and methods of use.

BACKGROUND

Temporary electrical power systems are typically used in scenarios inwhich access to the electrical grid does not exist at a particular siteor when the existing electrical grid does not satisfy the powerrequirements of the site. Examples include construction sites, miningsites, manufacturing sites, shipping locations, areas impacted bynatural disasters, temporary event locations, electric vehicle charging,and others (e.g., such as military installations, telecom sites, andresidential locations).

Traditional temporary electrical power systems comprise large industrialgas or diesel generators that are typically trailer or skid mounted anddelivered to the site in need of additional electrical power. Diesel andgas generators, which are powered by combustion engines, are noisy,expensive to maintain, and emit pollutants, such as carbon dioxide,which necessitates outdoor operation or substantial ventilation.Additionally, fuel levels must be monitored and when re-fueling isrequired, the generator must either be towed to a refueling station oron-site refueling must be arranged.

There are a variety of load profiles that can be found on temporarypower sites, and as a result, large diesel and gas generators come indifferent sizes (measured by the amount of power that can be generatedcontinuously). The typical voltage outputs in North America are 480 VAC3-Phase, 208 VAC 3-Phase, 240 VAC 1-Phase, and 120 VAC 1-Phase. Largergas or diesel generators typically have a voltage selector switch forthe user to set the desired electrical output. This voltage selectorswitch physically re-configures the poles on the alternator to form thedesired output. Because multiple types of outputs are used with multipleelectrical connections, it is sometimes not desirable to have allconnection points on the generator active, and therefore the commonpractice is to utilize circuit breakers to enable/disable outlets asdesired.

Traditional combustion temporary electrical power systems have a numberof disadvantages including emissions, noise levels, operating costs,maintenance costs, significantly reduced power conversion efficienciesat low loads, and expensive refueling. Diesel generators typically donot have the response capability to keep total harmonic distortion (THD)within allowable limits for high demand applications like tower cranes.Additionally, diesel generators for high demand applications need asubstantial resistor bank in order to not overspeed the engine. Thereexists a need for improved temporary electrical power systems thatprovide lower/zero emissions, near-silent operation, indoor operation,increased load flexibility, reduced maintenance requirements, and lowerfuel costs.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe claims that follow. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIGS. 1A-1D illustrate various views of one embodiment of anall-electric, battery-powered industrial generator.

FIG. 2 is a schematic diagram illustrating the various components andelectrical connections within the battery powered generator of FIGS.1A-1D.

FIGS. 3A-3D are schematic illustrations of a power system of thegenerator of FIGS. 1A-1D, including operation modes configured toproduce a user programmable output mode and/or user-selected outputs of480 VAC 3-phase, 208 VAC 3-phase, and 240 VAC single-phase.

FIGS. 4A-4F are schematic illustrations of another embodiment of a powersystem configured to produce user-selected outputs.

FIGS. 5A-5B are illustrations showing efficiency improvements obtainedby the power systems of this disclosure.

SUMMARY OF THE DISCLOSURE

An all-electric, battery powered mobile power unit is provided,comprising a DC electrical energy source, a power conversion systemcoupled to the DC electrical energy source, and an electronic controllerconfigured to control operation of the power conversion system toproduce a user-selected voltage output ranging from 100 VAC up to 500VAC and a user-selected phase configuration.

In some embodiments, the power conversion system comprises a highvoltage DC/DC converter electrically coupled to the electrical energysource, and a plurality of inverter stages electrically coupled to thehigh voltage DC/DC converter.

In one embodiment, the user-selected voltage output and phaseconfiguration is selected from the group consisting of 480 VAC 3-phase,208 VAC 3-phase, and 240 VAC single-phase.

In some embodiments, the user-selected phase configuration is selectedfrom the group consisting of single-phase and 3-phase.

In one example, when the user-selected voltage output and phaseconfiguration comprises 480 VAC 3-phase, the electronic controller isconfigured to control the high voltage DC/DC converter(s) to operate asa boost converter in which a primary battery voltage from the electricalenergy source is increased to a secondary voltage, and control theplurality of inverter stages to 277 VAC each and phase shift the outputsof the plurality of inverter stages to be 120 degrees apart.

In one example, the primary battery voltage from the electrical energysource comprises 300-450 VDC and the secondary voltage comprises 800VDC.

In one embodiment, a neutral line corresponding to a first output of afirst of the plurality of inverter stages is in phase with a line L1corresponding to a second output of a second of the plurality ofinverter stages, a line L2 corresponding to a third output of a third ofthe plurality of inverter stages is phase shifted by 120 degrees fromthe line L1, and a line L3 corresponding to a fourth output of a fourthof the plurality of inverter stages is phase shifted by 120 degrees fromthe line L2.

The electronic controller can be configured to provide the 480 VAC3-phase output to only a subset of electrical connections on aninterface panel of the mobile power unit. In some examples, theelectronic controller is configured to provide the 480 VAC 3-phaseoutput to only one or more tapered nose cam lock connectors or one ormore threaded fastener style connectors on the interface panel of themobile power unit. In another example, the electronic controller isconfigured to trigger circuit breakers associated with duplex connectorsor CS6365 connectors on the interface panel of the mobile power unit toprevent the 480 VAC 3-phase output from reaching the duplex connectorsor CS6365 connectors.

In another implementation, when the user-selected voltage output andphase configuration comprises 208 VAC 3-phase, the electronic controlleris configured to control the high voltage DC/DC converter to operate asa pass-through, in which a primary battery voltage from the electricalenergy source is provided as a secondary voltage, and control theplurality of inverter stages to phase shift the outputs of the pluralityof inverter stages to be 120 degrees apart.

In one embodiment, the primary battery voltage from the electricalenergy source comprises 300-450 VDC and the secondary voltage alsocomprises 300-450 VDC.

In one implementation, a neutral line corresponding to a first output ofa first of the plurality of inverter stages is in phase with a line L1corresponding to a second output of a second of the plurality ofinverter stages, a line L2 corresponding to a third output of a third ofthe plurality of inverter stages is phase shifted by 120 degrees fromthe line L1, and a line L3 corresponding to a fourth output of a fourthof the plurality of inverter stages is phase shifted by 120 degrees fromthe line L2.

In one example, the electronic controller is configured to provide the208 VAC 3-phase output to only a subset of electrical connections on aninterface panel of the mobile power unit. The electronic controller canbe configured to provide the 208 VAC 3-phase output to only one or moretapered nose cam lock connectors, one or more threaded fastener styleconnectors, or one or more duplex connectors on the interface panel ofthe mobile power unit. In one example, the electronic controller can beconfigured to trigger circuit breakers associated with CS6365 connectorson the interface panel of the mobile power unit to prevent the 208 VAC3-phase output from reaching the CS6365 connectors.

In another implementation, when the user-selected voltage output andphase configuration comprises 240 VAC single-phase, the electroniccontroller is configured to control the high voltage DC/DC converter tooperate as a pass-through, in which a primary battery voltage from theelectrical energy source is provided as a secondary voltage, and controlthe plurality of inverter stages to phase shift first and second outputsof the plurality of inverter stages to be 180 degrees apart.

In one example, the primary battery voltage from the electrical energysource comprises 300-450 VDC and the secondary voltage also comprises300-450 VDC.

In another implementation, a neutral line corresponding to a firstoutput of a first of the plurality of inverter stages is in phase with aline L1 corresponding to a second output of a second of the plurality ofinverter stages, and is in phase with a line L3 corresponding to a thirdoutput of a third of the plurality of inverter stages, a line L2corresponding to a fourth output of a fourth of the plurality ofinverter stages is phase shifted by 180 degrees from the neutral line,the line L1, and the line L3.

In one embodiment, the electronic controller is configured to providethe 240 VAC single-phase output to only a subset of electricalconnections on an interface panel of the mobile power unit. In oneexample, the electronic controller is configured to provide the 240 VACsingle-phase output to only one or more duplex connectors or one or moreCS6365 connectors on the interface panel of the mobile power unit. Inanother example, the electronic controller is configured to triggercircuit breakers associated with tapered nose cam lock connectors or thethreaded fastener style connectors on the interface panel of the mobilepower unit to prevent the 240 VAC single-phase output from reaching thetapered nose cam lock connectors or the threaded fastener styleconnectors.

A method of delivering a user-selected voltage output with anall-electric, battery powered industrial mobile power unit is provided,comprising the steps of receiving a desired voltage output ranging from100V AC up to 500V AC and a desired phase configuration from a user,controlling operation of a power conversion system of the mobile powerunit with an electronic controller of the mobile power unit to producethe desired voltage output and phase configuration.

In one embodiment, controlling operation of the power conversion systemfurther comprises controlling operation of a high voltage DC/DCconverter and a plurality of inverter stages of the mobile power unitwith the electronic controller.

In another embodiment, the desired voltage output and phaseconfiguration is selected from the group consisting of 480 VAC 3-phase,208 VAC 3-phase, and 240 VAC single-phase.

In some embodiments, the desired voltage output is between 100 VAC and500 VAC.

In other embodiments, the desired voltage output and the desired phaseconfiguration is provided to an appropriate subset of electricalconnections on an interface panel of the mobile power unit.

DETAILED DESCRIPTION

The present disclosure describes all-electric, battery-poweredindustrial or commercial grade mobile power units configured to supply avariety of user-selected power outputs, including a user programmableoutput, 480V 3-phase outputs, 208V 3-phase outputs, 240V single-phaseoutputs, and/or a regulated DC output. In some embodiments, the mobilepower unit can be configured to provide any customized or user-selectedelectrical output, including user selected voltage amplitudes,frequencies, phase shifts, or the like. The battery-powered mobile powerunits of the present disclosure are configured to be transported to atemporary power site to provide multiple power output options dependingon the specific need.

The industrial mobile power units described herein generally includeelectrical energy sources with DC output voltages and energy storagecapabilities that far exceed those found in consumer level battery packsand portable energy devices. These consumer devices are generallyintended for charging consumer electronic devices like smartphones,tablets, and laptop computers, and typically provide a variety ofstandard 110V single phase outputs and/or USB charging outputs withenergy storage options of up to around 2 kWh. In contrast, theindustrial mobile power units of the present disclosure provideelectrical energy sources with DC output voltages of up to 1000V DC,energy storage capabilities of up to or exceeding 600 kWh, 750 kWh, orgreater, with a plurality of user selectable voltage output and phaseconfigurations including a user programmable output, 480V 3-phaseoutputs, 208V 3-phase outputs, 240V single-phase outputs, and/or aregulated DC output. The industrial mobile power units of the presentdisclosure provide the user-selected or user-programmed voltage outputand phase configurations without using inefficient, expensive, and bulkycurrent and voltage transformers.

FIGS. 1A-1C are various views of one embodiment of an all-electricmobile power unit 100. FIG. 1A illustrates a rear-view of theall-electric mobile power unit, including a view of an interface panel102. The interface panel 102 can include, for example, a user interface104 such as a GUI, and a plurality of electrical connectors 106. Theuser interface is configured to provide an input and/or a display for auser to configure the mobile power unit into the desired operating mode,including selecting the desired electrical output and/orenabling/disabling one or more of the electrical connectors. In someembodiments, the desired electrical output is chosen by the user from apre-selected group of common electrical outputs (e.g., 480 VAC 3-Phase,208 VAC 3-Phase, 240 VAC 1-Phase, and 120 VAC 1-Phase). In anotherembodiment, the user can select any desired output voltage amplitude,frequency, and phase shift, allowing the mobile power unit to provideany user-selected electrical output. The mobile power unit can furtherbe configured to provide a regulated DC output (e.g., for electricvehicle charging). In some embodiments, instead of being integrated intothe interface panel, the user interface or GUI can be a remote device,such as a smartphone, tablet, or PC, which can be configured tocommunicate with and configure the mobile power unit via wirelesstechnologies such as Bluetooth, WiFi, cellular, etc. System parametersand configurations can also be displayed to the user on the remotedevice. As the mobile power unit is often used outdoors, the mobilepower unit can include a housing configured and designed to be exposedto the elements and general road conditions experienced by heavy dutytrucks and buses, and is therefore designed to be resistant toshock/vibration/salt spray etc.

The mobile power unit 100 can include an electrical energy sourcedisposed within the outer housing. In one configuration, the electricalenergy source comprises a plurality of lithium-ion battery cell groupsarranged in series connections. In other embodiments, the electricalenergy source can comprise other known energy storage devices, such asultracapacitors or fuel cells. While lithium-ion is presently thepreferred battery cell type, it should be understood that other batterycells can be used in place of lithium-ion cells as battery technologyevolves. In some examples, the electrical energy source can have anoperating voltage range of 300-450V. In other embodiments, theelectrical energy source can have a higher operating voltage range of450V-1000V DC.

FIGS. 1B-1C illustrate side and top views, respectively, of theall-electric mobile power unit 100. As shown, the mobile power unit caninclude a trailer 108 configured to attach to a trailer hitch or towvehicle, and a plurality of wheels 110 which allow for easy oftransportation and delivery of the mobile power unit to remote sites.Although the interface panel 102 is shown on the rear of the mobilepower unit in FIGS. 1A-1C, it should be understood that the interfacepanel can be positioned on any accessible surface of the mobile powerunit. The size of the mobile power unit can vary depending on the outputand energy storage capabilities, but in general, the mobile power unititself can range in size from approximately 50″ long, 30″ wide, and 50″tall up to 150″ long, 60″ wide, and 60″ tall. The trailer can add anextra 50-70″ in length and 20-30″ in height depending on the size andweight of the mobile power unit and the number and size of wheelsrequired to carry the weight of the mobile power unit. In a preferredembodiment, the mobile power unit 100 is approximately 100″ long, 40″wide, and 60″ tall, with the trailer adding an additional 40-50″ inlength and 15-30″ in height. In other embodiments, the mobile power unitcan be scaled up or down in terms of operating voltage range andoutputs, and the size of the mobile power unit can be adjustedaccordingly.

In some embodiments, the mobile power unit can include safety measuresto prevent movement/towing of the mobile power unit under certainconditions. For example, the mobile power unit can include a parkingbrake that can be automatically activated to prevent movement of themobile power unit. This parking brake may be automatically activatedwhen the mobile power unit is connected to a charging device, wheneverthe inverter is powered on, whenever other devices are plugged into andreceiving power from the mobile power unit, and/or whenever the mobilepower unit exits geofenced regions. For example, a construction or jobsite for a rental customer may be geofenced, and if the mobile powerunit leaves the geofenced region, the parking brake may be activated tokeep the mobile power unit at the approved jobsite or rental location.

FIG. 1D is a close-up view of the interface panel 102 of mobile powerunit 100, giving a better view of the user interface 104 and variouselectrical connectors 106 a-106 e. Referring to FIG. 1D, varying typesof electrical connectors can be provided on the interface paneldepending on the output and connection needs of the particular site. Forexample, the illustrated interface panel includes one or more NorthAmerican Non-Locking receptacles 106 a, one or more CS6365 receptacles106 b, one or more SAE J1772 connectors 106 c, one or more taper nosecam lock connectors 106 d, and/or one or more threaded fastener styleconnectors 106 e. As shown in FIG. 1D, the connectors 106 d and 106 ecan be configured to provide three-phase power outputs including lineends L1, L2, L3, active neutral line N, and a ground connection. Whilethe illustrated connectors describe a configuration in one embodiment,it should be understood that in other embodiments, other types ofelectrical connectors can be utilized on the interface panel 102. Due tothe nature of exposed connections for the terminal studs and cam locks,the interface panel can include a safety door with a position switchthat will not allow the mobile power unit to operate unless the safetydoor is closed. This safety door can further include a locking featureconfigured to allow placement of a physical lock to support lock out tagout (LOTO) safety protocols.

Referring still to FIG. 1D, the interface panel 102 can further includecircuit breakers 112, an emergency shutoff switch 114, and a voltageselector switch 116. The circuit breakers can be configured to preventdamage caused by excess current. In some implementations, each of theelectrical connectors can have its own circuit breaker. The emergencyshutoff switch 114 can be configured to shutoff/sever all electricaloutputs of the mobile power unit in case of an emergency. The interfacepanel can further include an optional voltage selector switch 116 toeasily switch between desired power outputs, such as between 480V3-phase, 208V 3-phase, and 240V single-phase outputs. In the illustratedembodiment the voltage selector switch is a physical interface on theinterface panel, but it should be understood that in other embodiments,the voltage selector switch can be implemented through the userinterface 104, such as with a graphical selector within a GUI. In otherembodiments, the user does not select from predetermined or pre-selectedoutput options, but instead can customize the electrical output to anyvoltage amplitude, frequency, and/or phase shift. This user-selectedcustom voltage output can be implemented through the user interface 104.

FIG. 2 is a schematic diagram illustrating the various components andelectrical connections within the battery powered mobile power unitdescribed above. Referring to FIG. 2, the mobile power unit can includean electrical energy source 218 which can comprise, for example, aplurality of battery cells as described above. The electrical energysource 218 can be electrically connected to a power distribution unit(PDU) 220, which includes a plurality of electrical inputs and outputsconfigured to distribute electrical power throughout the mobile powerunit. The PDU can be in a centralized location within the mobile powerunit for connection/disconnection/fusing of multiple electricalcomponents.

Battery management can be controlled with a battery management system(BMS) 222. The BMS 222 is configured to monitor the state of everybattery cell group and can measure any number of battery parameters,including voltage, temperature, current, etc. The BMS 222 is furtherconfigured to protect against over voltage, under voltage, measureresistance, estimate the state of charge, estimate the state of health,and measure power limits of each battery cell group. Additionally, theBMS is configured to monitor high voltage isolation resistance betweenthe high voltage DC components (such as the electrical energy source,the BMS, the PDU, etc.) and a chassis of the mobile power unit to ensurethat this isolation resistance is above acceptable thresholds. In theevent of an isolation fault, the BMS can be configured to shut-down thesystem until the fault is cleared by enabling/disabling the electricalenergy source.

The temperature measurement of the electrical energy source can be usedby the BMS for estimations and as safety limits for over temperature andcold temperature charging limits to prevent lithium plating. The BMS canalso be configured to perform cell group level balancing to maximize theperformance of the system.

Battery charging can be controlled with an on-board battery charger 224.As shown, the on-board battery charger can be electrically coupled toboth the PDU 220 and the electrical energy source 218 via the BMS 222.The battery charger is connected to/fused within the power PDU in casethere is a short circuit. The battery charger can be air or liquidcooled and can be configured to regulate itself (i.e., if anover-temperature event were to occur the battery charger canautomatically shut-down). The battery charger can communicate with theBMS 222 to regulate the charge current and ensure no cells in theelectrical energy source are over-charged.

The mobile power unit can be configured to utilize existing electricvehicle charging infrastructure and components (the Combined ChargingSystem, or CCS) to charge its battery energy source. Therefore, anoptional CCS controller 224 can facilitate charging on the CCS networkvia an AC power source or alternatively via an off-board DC fastcharger. The CCS controller 224 can be coupled to/configured tocommunicate with the BMS 222 and the electrical connector 206 c tocontrol the AC and/or DC charging of the electrical energy source on theCCS.

Charging of the electrical energy source 218 from external power sourcescan be accomplished via an electrical connector 206 c on the interfacepanel of the mobile power unit. For example, a SAE J1772, such as theone described above in FIG. 1D, can be connected to an external powersource to charge the mobile power unit. It should be understood thatother electrical connector types can be used for charging the mobilepower unit.

The mobile power unit can further include an overall system controlleror electronic control unit (ECU) 226 which can configure/control theoverall operation of the mobile power unit. In some embodiments, thecontroller can be integrated into the user interface or GUI describedabove. The system controller or ECU 226 can communicate with the othermicrocontrollers of the mobile power unit (such as the BMS 222, the CCScontroller 224, etc.) via a Controller Area Network (CAN bus), forexample. A low voltage DC/DC converter 228 can be used to regulate thevoltage for the controllers and microcontrollers of the mobile powerunit. For example, the low voltage DC/DC converter can convert the highvoltage from the electrical energy source (e.g., 300-450V) to a muchlower voltage (e.g., 12V) for the controllers and microcontrollers tooperate on. The system controller can monitor all functions and featuresof the mobile power unit, and can be configured to communicateinformation to a distribution center via wired or wirelesscommunication. For example, the system controller can monitor andcommunicate information relating to the mobile power unit or batteryenergy source, such state of charge, state of health, temperature, etc.to a remote location.

Operation of the mobile power unit and its configurable, variableoutputs will now be discussed. Referring still to FIG. 2, the mobilepower unit can further include a high voltage DC/DC converter 230electrically coupled to the PDU 220. The high voltage DC/DC convertercan be configurable to operate in a plurality of different modes. In onespecific embodiment, the high voltage DC/DC converter can operate in twodistinct configurations. For example, in a first configuration, the highvoltage DC/DC converter can operate as a boost converter in which it isconfigured to boost the unregulated battery energy source voltage (e.g.,an unregulated battery voltage of 300-450V) up to an elevated DC voltagethat is regulated (e.g., such as up to a regulated 750-850V DC).Similarly, if the unregulated battery energy source voltage is lowerthan it should be (e.g., the expected source voltage is at least 325V,but the actual source voltage is lower), the boost converter could beconfigured to increase the source voltage to the expected sourcevoltage. In some embodiments, the high voltage DC/DC converter can beconfigured to slowly ramp-up from the battery voltage to the highervoltage to avoid hard starting the system. In the second configuration,the high voltage DC/DC converter can operate as a pass-through, in whichthe output voltage is the same as the battery source voltage (e.g., anunregulated 300-450V). In other embodiments, it may be desirable toreduce the unregulated battery energy source voltage to a reduced DCvoltage. For example, some embodiments of the mobile power unit includean energy source with a source voltage of up to 800V. In theseimplementations, it would therefore be necessary for the DC/DC converterto reduce the source voltage down to 300-450V in order to be able toproduce all the desired voltage outputs. In these embodiments, the DC/DCconverter could be, for example, a buck converter.

The mobile power unit can further comprise one or more inverter stages,or alternatively, a multi-stage inverter, electrically coupled to theoutput of the high voltage DC/DC converter. While these inverter stagesare illustrated as inverter stages 232 a-232 d in FIG. 2, it should beunderstood that any number of inverter stages can be implementeddepending on the desired output of the mobile power unit. In someembodiments, the inverter stages can utilize the same hardware as thehigh voltage DC/DC converter, but can instead be controlled differentlythrough specific CAN bus commands from the system controller or ECU 226.In other embodiments, the inverter stages can implement differentelectrical topologies than illustrated/described herein. Each inverterstage has a DC input from the high voltage DC/DC converter and isconfigured to create an AC output utilizing 3-phases. In one specificimplementation, each phase can support a current of 32A for a totalcurrent of 96A peak per phase (e.g., if the inverter stages are operatedin parallel as a single phase). According to the present disclosure, thesystem controller or ECU is configured to combine the plurality ofinverter stages at various phase shifts to create 3-phase andsplit-phase outputs, which are passed to the interface panel and theelectrical connections as described above.

FIGS. 3A-3D illustrate one embodiment of a power system schematic of themobile power unit as described above. These schematics illustrate howthe various power outputs of the mobile power unit are delivered to theinterface panel and electrical connectors of the mobile power unit.Referring to FIG. 3A, the mobile power unit can include the features andcomponents described above in FIGS. 1D and 2, including NEMA receptacles306 a, CS6365 receptacles 306 b, SAE J1772 connector 306 c, taper nosecam lock connectors 306 d, threaded fastener style connectors 306 e,circuit breakers 312, battery energy source 318, PDU 320, CCS controller324, low voltage DC/DC converter 328, high voltage DC/DC converter 330,and multi-stage inverter 332. While the system controller or ECU is notshown in this power system schematic, it should be understood that thesystem controller or ECU is configured to control the overall operationof the mobile power unit, including issuing commands to the varioussystem components including the other microcontrollers, the high voltageDC/DC converter, and the multi-stage inverter. As shown, the multi-stageinverter 332 comprises four individual inverter stages with outputs N,L1, L2, and L3, but it should be understood that other implementationsof multi-stage inverters or a plurality of single stage inverters can beimplemented and remain within the scope of this disclosure.

FIG. 3B illustrates the power system schematic of the mobile power unitin which the mobile power unit is configured to output a 480V AC 3-phaseoutput to the interface panel and electrical connectors of the mobilepower unit. In this operating mode, the ECU is configured to control thehigh voltage DC/DC converter to operate as a boost converter in which itis configured to boost the electrical energy source voltage (e.g., abattery voltage of 300-450V DC as shown) up to an elevated DC voltagethat is regulated (e.g., a regulated voltage of 750V-1000V DC as shown).For example, the DC/DC converter can be a boost converter, and the ECUcan control the boost converter to operate in boost mode to increase thevoltage.

Referring still to FIG. 3B, with an input voltage of 750V DC as shown,each of the inverter stages is configured to create a 277V AC outputwith 35 kW of inverter power. A first inverter stage creates an activeneutral line N, a second inverter stage creates line L1 with a 277 VACoutput shifted by 0 degrees, a third inverter stage creates line L2 witha 277 VAC output shifted by 120 degrees, and a fourth inverter stagecreates line L3 with a 277 VAC output shifted by 240 degrees. The systemcontroller or ECU is configured to phase shift the outputs of eachinverter stage (e.g., via the CAN bus) to be 120 degrees apart, asshown. The phase shifted 277 VAC outputs from lines L1, L2, and L3 thenare combined to form the 480 VAC 3-Phase output. For this mode, thelimiting factor is the high voltage DC/DC converter's current limit,therefore it is suggested to not to use the duplex connectors or CS6365connectors when outputting the 480V AC 3-phase output, but only, forexample, the tapered nose cam lock connectors 306 d or the threadedfastener style connectors 306 e. It should be understood that the DC/DCconverter could be changed to increase the overall power level of thesystem. In some implementations, the circuit breakers 312 that are tiedto the duplex outlets 306 a and/or the CS6365 outlets 306 b can betriggered, either manually or automatically, to disable the electricalconnectors 306 a and 306 b.

FIG. 3C illustrates the power system schematic of the mobile power unitin which the mobile power unit is configured to output a 208V AC 3-phaseoutput to the interface panel and electrical connectors of the mobilepower unit. In this operating mode, the ECU is configured to control thehigh voltage DC/DC converter to operate as a pass-through, in which theoutput voltage is roughly the same as the battery source voltage (e.g.,an unregulated 300-450V DC). It should be understood that in realoperating conditions, the pass-through switch will add some resistanceto the circuit which will effectively reduce the voltage from thebattery by up to 5V. For example, the ECU can control the high voltageDC/DC converter to operate as a pass-through to produce an unregulatedoutput with the same voltage as the electrical energy source (e.g.,325-450V DC).

Referring still to FIG. 3C, with an input voltage of 325-450V DC asshown, each of the inverter stages is configured to create a 120V ACoutput referenced to neutral with 35 kW of inverter power. A firstinverter stage creates an active neutral line N, a second inverter stagecreates line L1 with a 120 VAC output shifted by 0 degrees, a thirdinverter stage creates line L2 with a 120 VAC output shifted by 120degrees, and a fourth inverter stage creates line L3 with a 120 VACoutput shifted by 240 degrees. The system controller or ECU isconfigured to phase shift the outputs of each inverter stage (e.g., viathe CAN bus) to be 120 degrees apart, as shown. The phase shifted 120VAC outputs from lines L1, L2, and L3 then are combined to form the 208VAC 3-Phase output. For this mode, the limiting factor is the inverterstage current limits, therefore it is suggested to not to use the CS6365connectors when outputting the 208V AC 3-phase output but only, forexample, the tapered nose cam lock connectors 306 d, the threadedfastener style connectors 306 e, or the duplex connectors 306 a. In someimplementations, the circuit breakers 312 that are tied to the CS6365connectors 306 b can be triggered, either manually or automatically, todisable the electrical connectors 306 b.

FIG. 3D illustrates the power system schematic of the mobile power unitin which the mobile power unit is configured to output a 240V ACsingle-phase output to the interface panel and electrical connectors ofthe mobile power unit. In this operating mode, the ECU is configured tocontrol the high voltage DC/DC converter to operate as a pass-through,in which the output voltage is the roughly the same as the batterysource voltage (e.g., an unregulated 325-450V DC). For example, the ECUcan control the high voltage DC/DC converter to close the upper gatesand allow the lower gates to pass current, as shown, produces anunregulated output with the same voltage as the electrical energy source(e.g., 325-450V DC).

Referring still to FIG. 3D, with an input voltage of 325-450V DC asshown, each of the inverter stages is configured to create a 120V ACoutput referenced to neutral with 23 kW of inverter power. A firstinverter stage creates an active neutral line N, a second inverter stagecreates line L1 with a 120 VAC output shifted by 0 degrees, a thirdinverter stage creates line L2 with a 120 VAC output shifted by 180degrees, and a fourth inverter stage creates line L3 with a 120 VACoutput shifted by 0 degrees. The system controller or ECU is configuredto phase shift the outputs of the inverter stage associated with line L1and line L2 (e.g., via the CAN bus) to be 180 degrees apart, as shown.The phase shifted 120 VAC outputs from lines L1, L2, and L3 then arecombined to form the 240 VAC single-Phase output. The ECU can be furtherconfigured to cause the inverter stage associated with line L3 tooperate in phase with line L1. In one embodiment, lines L1 and L2 can beconfigured to power the split phase CS6365 electrical connectors 306 b,and line L3 can power one of the duplex outlets 306 a. For this mode,the limiting factor is the inverter stage current limits, therefore itis suggested to not to use the tapered nose cam lock connectors 306 d orthe threaded fastener style connectors 306 e when outputting the 240V ACsingle-phase output, but only, for example, the duplex connectors 306 aor the CS6365 connectors 306 b. In some implementations, the circuitbreakers 312 that are tied to the tapered nose cam lock connectors 306 dor the threaded fastener style connectors 306 e can be triggered, eithermanually or automatically, to disable the electrical connectors 306 dand 306 e.

In some embodiments, the mobile power unit can be configured to outputany user-selected or user-chosen electrical output. In this embodiment,the user can select, via the user interface, any desired output voltageamplitude, frequency, and/or phase shift, allowing the mobile power unitto provide any user-selected electrical output. For example, in someregions, such as North America, commonly desired output voltages are 480VAC 3-Phase, 208 VAC 3-Phase, 240V 1-Phase, and 120V 1-Phase, all at afrequency of 60 Hz. In other regions the desired output voltage may be400V-3 Phase, 230V-1 Phase, 110V-1 Phase all at 50 Hz.

As described above, an optional boost converter and the inverter stagesin combination with customized phase shifts (via the CAN bus) can beconfigured to provide customizable/configurable electrical outputs. Forexample, in the embodiment of FIG. 3B described above, the batteryvoltage is boosted with a boost converter and then the outputs of eachinverter stage are phase shifted by 120 degrees to achieve the 480 VAC3-Phase output. The same methodology can be used to produce any desiredelectrical output, within the hardware limitations of the mobile powerunit. Generally, however, the mobile power unit can be configured toprovide AC voltages between about 100V up to about 500V, and generallybetween a frequency of 50 Hz and 60 Hz. However, in some embodiments,the mobile power unit can operate at frequencies up to 400 Hz (commonlyused in military applications). Customized and automated voltages,frequencies, and phase shifts on lines L1, L2, and L3 can be specifiedby the end user then automatically configured by the mobile power unit(e.g., by one or more of the electronic controllers or the CAN bus) toachieve the desired voltage output.

The phases may also be controlled independently of one another in orderto create less common output voltages such as “Wide Leg 240V” in whichLine 1 has a L-N Voltage of 120V, Line 2 has a L-N Voltage of 208V, andLine 3 has a L-N Voltage of 120V. The Line 1 to Line 3 voltage is 240Vwhich means they are 180 degrees out of phase. Table 1 describes thevarious amplitudes, frequency, and phase shift for a “Wide Leg 240V”output:

TABLE 1 Amplitude Amplitude Wide Leg 240 (L-N) (L-L) Frequency PhaseShift Line 1 120 V 240 V 60 Hz  0 Degrees Line 2 208 V 240 V 60 Hz 120Degrees Line 3 120 V 240 V 60 Hz 180 Degrees

In another embodiment the user can increase and decrease the outputvoltage setpoint of the unit as desired. This feature can be useful forcompensating for line losses over a long cable distance.

The general range of voltages for common AC power transmission isbetween 100V up to 480V and 50 Hz or 60 Hz. Specialized equipment suchas aircraft, ships, may require other AC power sources such as 120V at400 Hz or 450V 400 Hz. For other applications where it is desired forthe phases to be in sync such as powering RV's, two lines can be set to120V with 0 Degrees of phase shift. The other two outputs can both beset to active neutral in order to maximize the system capabilities. Asdescribed above, the user can input the desired output through the useof a human machine interface (HMI) such as a touch screen or remotelythrough an external device.

The techniques described above include controlling a DC/DC converter anda plurality of inverter stages to achieve the desired voltage and phaseoutput. For example, as described above, the DC/DC converter can beoperated as a boost converter to boost an input voltage of 325-450V to avoltage of 750-800V, and then the inverter stages can be controlled tocreate a 480V 3-phase output. Similarly, the DC/DC converter can beoperated as a pass-through to pass the 325-450V input voltage to theinverter stages, which can then be controlled to produce a 208V 3-phaseoutput (e.g., FIG. 3C) or a 240V single-phase output (e.g., FIG. 3D). Itshould be understood that other implementations can be used when theinput voltage, such as the voltage from the battery source, is lower orhigher than the 325-450V range described above. For example, if thebattery source has a voltage on the order of 750-800V, the DC/DCconverter can instead comprise a buck converter. In this embodiment, toproduce the 480V 3-phase output, the DC/DC converter can be operated asa pass-through (e.g., the 750-800V voltage from the battery is passedthrough to the inverter stages). Alternatively, to produce the 208V3-phase output or the 240V single-phase output, the DC/DC converter canbe operated as a buck converter, and the battery voltage can be reducedfrom the 750-800V down to the desired 325-450V voltage, which can thenbe used by the inverter stages to produce the desired output.

While the specific embodiments described above in FIGS. 3A-3D areconfigured to output between 23kVA-80kVA of inverter power depending onthe configuration, alternative designs can be implemented which increasethe inverter power output. Referring to the embodiment of FIG. 4A, apower system schematic for a mobile power unit is shown in which a pairof high-voltage DC/DC converters 430 arranged in parallel with the PDU420 are configured to produce a 480V 3-phase output with 80kVA ofinverter power via the multi-stage inverter 432. A first inverter stagecreates an active neutral line N, a second inverter stage creates lineL1 with a 277 VAC output, a third inverter stage creates line L2 with a277 VAC output, and a fourth inverter stage creates line L3 with a 277VAC output. These stages can be combined as described above in FIG. 3Bwith appropriate phase shifts to produce a 480V 3-phase output, with anincreased power output of 80kVA compared to the example above.

FIG. 4B illustrates a power schematic in which the multi-stage inverteris arranged to produce a 240V single-phase output with up to 46 kW ofinverter power. In this arrangement, a single high-voltage DC/DCconverter 430 is connected to the PDU 420 and to the multi-stageinverter 432. A first inverter stage creates an active neutral line N, apair of inverter stages in parallel create line L1 with a 120 VACoutput, and a pair of inverter stages in parallel create line L2 with a120 VAC output, which can be combined with a phase shift of 180 degreesto create the overall output of 240V single-phase.

FIG. 4C illustrates a power schematic in which the multi-stage inverteris arranged to produce a 208V 3-phase output with up to 34 kW ofinverter power. In this arrangement, a single high-voltage DC/DCconverter 430 is connected to the PDU 420 and to the multi-stageinverter 432. A first inverter stage creates an active neutral line N, asecond inverter stage creates line L1 with a 120 VAC output, a thirdinverter stage creates line L2 with a 120 VAC output, and a fourthinverter stage creates line L3 with a 120 VAC output. When the DC/DCconverter 430 is bypassed with a DC/DC bypass switch 429, these stagescan be combined with a phase shift of 120 degrees to produce a 208V3-phase output with a power output of 34 kW.

FIG. 4D illustrates a power schematic in which the multi-stage inverteris arranged to produce a 240V single-phase output with up to 46 kW ofinverter power. In this arrangement, a single high-voltage DC/DCconverter 430 is connected to the PDU 420. A first inverter stagecreates an active neutral line N, a pair of inverter stages in parallelcreate line L1 with a 120 VAC output, and a pair of inverter stages inparallel create line L2 with a 120 VAC output, which can be combinedwith a phase shift of 180 degrees to create the overall output of 240Vsingle-phase. The DC/DC converter 430 can be bypassed with DC/DC bypassswitch 429 as shown.

The concepts described above can be combined to provide a dynamicreconfiguration that provides 80 kW of power output at 480V 3-phase andup to 46 kW of power output at 240V 3-phase. Referring to FIG. 4E, apower schematic is shown in which the multi-stage inverter can beconfigured to produce a 480V 3-phase output with 80 kW of power in afirst configuration in which Switch 431 is closed and Switch 433 isopen, and can also be configured to produce a 240V single-phase outputwith up to 46 kW of inverter power in a second configuration in whichSwitch 431 is open and Switch 433 is closed. In the 480V mode, theinverter stage 432 a acts as a boost converter in parallel, and in the240V mode, the inverter stage 432 a acts as an inverter stage.

FIG. 4F is another power schematic for a mobile power unit withadditional features. As with the schematics above, the mobile power unitcan include an electrical energy source 418, one or more DC/DCconverters 430, and a plurality of inverter stages 432. The outputs fromthe plurality of inverter stages 432 can optionally pass through acommon mode line filter 434 before being output (e.g., at the outlets ofthe mobile power unit as described above).

In one embodiment, the power conversion system can output a regulated DCvoltage 436 directly from the DC/DC converter(s) 430. The DC/DCconverter(s) can be configured to regulate the current between theelectrical energy source of the mobile power unit and another electricalenergy source, such as a battery pack of an electric vehicle. This canbe used for DC charging other devices such as an electric vehicle.

Still referring to FIG. 4F, the mobile power unit can include anauxiliary inverter 438 that can be configured to provide an electricaloutput 439 to an auxiliary power panel 440. In some embodiments, forexample, this auxiliary power panel can provide simple 110 VAC 1-Phaseoutputs (e.g., standard north American power outlets). The auxiliaryinverter 438 provides these outputs regardless of what operating mode oroutputs are being provided the other plurality of inverters 432 of themobile power unit. In some embodiments, the output passes through acommon mode line filter 434 before going to the auxiliary power panel.

In some embodiments, the auxiliary inverter 438 can be used to rechargethe electrical energy source 418 via grid power. Referring still to FIG.4F, the mobile power unit can be hooked up to grid power with charginginlet 442. The AC power from the charging inlet can pass through apre-charge relay box 444, when can then pass through the auxiliaryinverter 438 to convert the AC signal to a DC voltage. the auxiliaryinverter can then be configured to regulate the charging of theelectrical energy source 418 without the need for dedicated chargingcontrollers and hardware within the mobile power unit.

In another embodiment, still referring to FIG. 4F, a user can select ifthey desire the electrical neutral connection to be floating orgrounding. If it is desired to be grounded, a relay 446 is configured toopen to connect the neutral line to the chassis ground at a singlesource point. If the user instead desires a floating connection, therelay can be opened so that the neutral line will not be coupled to thechassis ground.

The mobile power units described herein provide large gains inefficiency compared to typical diesel generators. As shown in FIGS.5A-5B, a typical diesel generator has a very low PCS conversionefficiency. Transformers further reduce the efficiency of these designs(with a typical transformer efficiency of 95%). Thus, a typical systemrequires up to 670 kWh of energy storage to be able to deliver 550 kWhof energy output. In comparison, embodiments of the systems describedherein require only 620 kWh of energy storage capacity to provide anoutput of 550 kWh, providing a 50 kWh advantage over prior systems.These efficiencies allow the systems described herein to be produced ata lower cost and potentially at a smaller size compared to conventionalsystems, while also providing energy efficiency and emissions benefitsas discussed.

The mobile power unit described above, including the electricalcomponents, can utilize advanced silicon carbide (SiC) switchingtechnology which allows it to operate at very high frequencies, thusenabling high-efficiency and low magnetic component sizes. In certainlow power situations, it may be desirable for each inverter stage toreduce to 2 or even 1 phase in order to reduce switching losses andimprove efficiency. This strategy is known as “phase shedding.”

As for additional details pertinent to the present invention, materialsand manufacturing techniques may be employed as within the level ofthose with skill in the relevant art. The same may hold true withrespect to method-based aspects of the invention in terms of additionalacts commonly or logically employed. Also, it is contemplated that anyoptional feature of the inventive variations described may be set forthand claimed independently, or in combination with any one or more of thefeatures described herein. Likewise, reference to a singular item,includes the possibility that there are plural of the same itemspresent. More specifically, as used herein and in the appended claims,the singular forms “a,” “and,” “said,” and “the” include pluralreferents unless the context clearly dictates otherwise. It is furthernoted that the claims may be drafted to exclude any optional element. Assuch, this statement is intended to serve as antecedent basis for use ofsuch exclusive terminology as “solely,” “only” and the like inconnection with the recitation of claim elements, or use of a “negative”limitation. Unless defined otherwise herein, all technical andscientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which this inventionbelongs. The breadth of the present invention is not to be limited bythe subject specification, but rather only by the plain meaning of theclaim terms employed.

1. An all-electric, battery powered mobile power unit, comprising: a DCelectrical energy source; a power conversion system coupled to the DCelectrical energy source, wherein the power conversion system includes aplurality of inverter stages and does not include a transformer; and anelectronic controller configured to control operation of the powerconversion system to produce a user-selected voltage output ranging from100 VAC up to 500 VAC and a user-selected phase configuration.
 2. Themobile power unit of claim 1, wherein the power conversion systemcomprises: a high voltage DC/DC converter electrically coupled to the DCelectrical energy source; and wherein the plurality of inverter stagesare electrically coupled to the high voltage DC/DC converter.
 3. Themobile power unit of claim 1, wherein the user-selected phaseconfiguration is selected from the group consisting of single-phase and3-phase.
 4. The mobile power unit of claim 1, wherein the user-selectedvoltage output and phase configuration is selected from the groupconsisting of 480 VAC 3-phase, 208 VAC 3-phase, and 240 VACsingle-phase.
 5. The mobile power unit of claim 4, wherein when theuser-selected voltage output and phase configuration comprises 480 VAC3-phase, the electronic controller is configured to: control the highvoltage DC/DC converter to operate as a boost converter in which aprimary battery voltage from the DC electrical energy source isincreased to a secondary voltage; and control the plurality of inverterstages to phase shift the outputs of the plurality of inverter stages tobe 120 degrees apart.
 6. The mobile power unit of claim 5, wherein theprimary battery voltage from the DC electrical energy source comprises300-450 VDC and the secondary voltage comprises 800 VDC.
 7. The mobilepower unit of claim 5, wherein: a neutral line corresponding to a firstoutput of a first of the plurality of inverter stages is in phase with aline L1 corresponding to a second output of a second of the plurality ofinverter stages; a line L2 corresponding to a third output of a third ofthe plurality of inverter stages is phase shifted by 120 degrees fromthe line L1; and a line L3 corresponding to a fourth output of a fourthof the plurality of inverter stages is phase shifted by 120 degrees fromthe line L2.
 8. The mobile power unit of claim 7, wherein the electroniccontroller is configured to provide the 480 VAC 3-phase output to only asubset of electrical connections on an interface panel of the mobilepower unit.
 9. The mobile power unit of claim 8, wherein the electroniccontroller is configured to provide the 480 VAC 3-phase output to onlyone or more tapered nose cam lock connectors or one or more threadedfastener style connectors on the interface panel of the mobile powerunit.
 10. The mobile power unit of claim 9, wherein the electroniccontroller is configured to trigger circuit breakers associated withduplex connectors or CS6365 connectors on the interface panel of themobile power unit to prevent the 480 VAC 3-phase output from reachingthe duplex connectors or CS6365 connectors.
 11. The mobile power unit ofclaim 4, wherein when the user-selected voltage output and phaseconfiguration comprises 208 VAC 3-phase, the electronic controller isconfigured to: control the high voltage DC/DC converter to operate as apass-through, in which a primary battery voltage from the DC electricalenergy source is provided as a secondary voltage; and control theplurality of inverter stages to phase shift the outputs of the pluralityof inverter stages to be 120 degrees apart.
 12. The mobile power unit ofclaim 11, wherein the primary battery voltage from the DC electricalenergy source comprises 300-450 VDC and the secondary voltage alsocomprises 300-450 VDC.
 13. The mobile power unit of claim 11, wherein: aneutral line corresponding to a first output of a first of the pluralityof inverter stages is in phase with a line L1 corresponding to a secondoutput of a second of the plurality of inverter stages; a line L2corresponding to a third output of a third of the plurality of inverterstages is phase shifted by 120 degrees from the line L1; and a line L3corresponding to a fourth output of a fourth of the plurality ofinverter stages is phase shifted by 120 degrees from the line L2. 14.The mobile power unit of claim 11, wherein the electronic controller isconfigured to provide the 208 VAC 3-phase output to only a subset ofelectrical connections on an interface panel of the mobile power unit.15. The mobile power unit of claim 14, wherein the electronic controlleris configured to provide the 208 VAC 3-phase output to only one or moretapered nose cam lock connectors, one or more threaded fastener styleconnectors, or one or more duplex connectors on the interface panel ofthe mobile power unit.
 16. The mobile power unit of claim 15, whereinthe electronic controller is configured to trigger circuit breakersassociated with CS6365 connectors on the interface panel of the mobilepower unit to prevent the 208 VAC 3-phase output from reaching theCS6365 connectors.
 17. The mobile power unit of claim 4, wherein whenthe user-selected voltage output and phase configuration comprises 240VAC single-phase, the electronic controller is configured to: controlthe high voltage DC/DC converter to operate as a pass-through, in whicha primary battery voltage from the DC electrical energy source isprovided as a secondary voltage; and control the plurality of inverterstages to phase shift first and second outputs of the plurality ofinverter stages to be 180 degrees apart.
 18. The mobile power unit ofclaim 17, wherein the primary battery voltage from the DC electricalenergy source comprises 300-450 VDC and the secondary voltage alsocomprises 300-450 VDC.
 19. The mobile power unit of claim 17, wherein: aneutral line corresponding to a first output of a first of the pluralityof inverter stages is in phase with a line L1 corresponding to a secondoutput of a second of the plurality of inverter stages, and is in phasewith a line L3 corresponding to a third output of a third of theplurality of inverter stages; a line L2 corresponding to a fourth outputof a fourth of the plurality of inverter stages is phase shifted by 180degrees from the neutral line, the line L1, and the line L3.
 20. Themobile power unit of claim 19, wherein the electronic controller isconfigured to provide the 240 VAC single-phase output to only a subsetof electrical connections on an interface panel of the mobile powerunit.
 21. The mobile power unit of claim 20, wherein the electroniccontroller is configured to provide the 240 VAC single-phase output toonly one or more duplex connectors or one or more CS6365 connectors onthe interface panel of the mobile power unit.
 22. The mobile power unitof claim 20, wherein the electronic controller is configured to triggercircuit breakers associated with tapered nose cam lock connectors or thethreaded fastener style connectors on the interface panel of the mobilepower unit to prevent the 240 VAC single-phase output from reaching thetapered nose cam lock connectors or the threaded fastener styleconnectors.
 23. The mobile power unit of claim 1, wherein theuser-selected voltage output comprises any chosen voltage between 100VAC and 500 VAC.
 24. The mobile power unit of claim 1, wherein the DCelectrical energy source comprises at least 600 kWh of energy storage.25. The mobile power unit of claim 1, wherein the DC electrical energysource comprises at least 500 kWh of energy storage.
 26. The mobilepower unit of claim 1, wherein the DC electrical energy source comprisesat least 750 kWh of energy storage.
 27. A method of delivering auser-selected voltage output with an all-electric, battery poweredindustrial mobile power unit, comprising the steps of: receiving adesired voltage output ranging from 100V AC up to 500V AC and a desiredphase configuration from a user; controlling operation of a powerconversion system of the mobile power unit with an electronic controllerof the mobile power unit to produce the desired voltage output and thedesired phase configuration without using a transformer.
 28. The methodof claim 27, wherein controlling operation of the power conversionsystem further comprises controlling operation of a high voltage DC/DCconverter and a plurality of inverter stages of the mobile power unitwith the electronic controller.
 29. The method of claim 27, wherein thedesired voltage output and phase configuration is selected from thegroup consisting of 480 VAC 3-phase, 208 VAC 3-phase, and 240 VACsingle-phase.
 30. The method of claim 27, wherein the desired voltageoutput is between 100 VAC and 500 VAC.